NOTE: For detailed information on purchasing options, contact your
local Allegro field applications engineer or sales representative.
Allegro MicroSystems, Inc. reserves the right to make, from time to time, revisions to the anticipated product life cycle plan
for a product to accommodate changes in production capabilities, alternative product availabilities, or market demand. The
information included herein is believed to be accurate and reliable. However, Allegro MicroSystems, Inc. assumes no respon-
sibility for its use; nor for any infringements of patents or other rights of third parties which may result from its use.
Recommended Substitutions:
Dual Full-Bridge PWM Motor Driver
2916
For existing customer transition, and for new customers or new appli-
cations, refer to the A4970.
Date of status change: January 30, 2012
This device is no longer in production. The device should not be
purchased for new design applications. Samples are no longer available.
Discontinued Product
Description
The UDx2916 motor drivers drive both windings of a bipolar
stepper motor or bidirectionally control two DC motors.
Both bridges are capable of sustaining 45 V and include
internal pulse-width modulation (PWM) control of the
output current to 750 mA. The outputs have been optimized
for a low output saturation voltage drop (less than 1.8 V
total source plus sink at 500 mA).
For PWM current control, the maximum output current is
determined by user selection of a reference voltage and sensing
resistor. Two logic-level inputs select output current limits of
0%, 33%, 67%, or 100% of the maximum level. A PHASE
input to each bridge determines load current direction.
The bridges include both ground-clamp and flyback diodes for
protection against inductive transients. Internally generated
delays prevent crossover currents when switching current
direction. Special power-up sequencing is not required. Thermal
protection circuitry disables the outputs if the chip temperature
exceeds safe operating limits.
The device is supplied in a 24-pin dual in-line plastic (DIP,
package B) with two pairs of batwing leads as heat-sinkable
tabs for enhanced power dissipation capabilities. The LB
package is a 24-lead surface-mount wide SOIC with two pairs
29319.20R
Features and Benefits
▪ 750 mA continuous output current
▪ 45 V output sustaining voltage
▪ Internal clamp diodes
▪ Internal PWM current control
▪ Low output saturation voltage
▪ Internal thermal shutdown circuitry
▪ Similar to dual PBL3717 or UC3770
Dual Full-Bridge PWM Motor Driver
Continued on the next page…
Packages
Not to scale
2916
Package B 24-pin
Batwing DIP
Package LB 24-pin
Batwing SOICW
Package EB 44-pin PLCC
with internally-fused leads
PWM Current-Control Circuitry
V
REF
Dwg. EP-007B
V
BB
SENSE ONE
SHOT
SOURCE
DISABLE
RC
–
+
I
0
I
1
w10
E
OUT A
OUTB
'B' PACKAGE,
CHANNEL 1
PIN NUMBERS
SHOWN.
RC
RSRT
CC
CT
24
20 k7
40 k7
10 k7
21
1
23
22
14
20
17
15
Dual Full-Bridge Motor Driver
2916
2
Allegro MicroSystems, Inc.
115 Northeast Cutoff, Box 15036
Worcester, Massachusetts 01615-0036 (508) 853-
5000
www.allegromicro.com
Selection Guide
of batwing leads. The EB package is a 44-lead power PLCC with 11
internally-fused leads on two sides. Their webbed-lead construction
provides for maximum package power dissipation in the smallest
possible construction.
The devices are available for operation from –20°C to 85°C (range N),
and from –40°C to 105°C (range Q). All packages are lead (Pb) free,
with 100% matte tin leadframe plating.
Description (continued)
Part Number Package Packing Ambient Temperature
(°C)
UDN2916B-T124-pin batwing DIP 15 per tube
–20 to 85UDN2916EBTR-T144-pin internally fused lead PLCC 450 per reel
UDN2916LBTR-T224-pin batwing SOICW 1000 per reel
UDQ2916LBTR-T224-pin batwing SOICW 1000 per reel –40 to 105
1This variant is in production, however, it has been deemed Pre-End of Life. The product is approaching end of life. Within
a minimum of 6 months, the device will enter its fi nal, Last Time Buy, order phase. Status change: November 1, 2010.
2This variant is in production, however, it has been deemed Pre-End of Life. The product is approaching end of life. Within
a minimum of 6 months, the device will enter its fi nal, Last Time Buy, order phase. Status change: January 31, 2011.
Absolute Maximum Ratings
Characteristic Symbol Notes Rating Units
Motor Supply Voltage VBB 45 V
Logic Supply Voltage VCC 7.0 V
Input Voltage VIN –0.3 to VCC + 0.3 V
Output Emitter Voltage VE1.5 V
Output Current* IOUT
Peak Output current rating may be limited by duty
cycle, ambient temperature, and heat sinking.
Under any set of conditions, do not exceed the
specified current rating or TJ(max)
1.0 A
Continuous 750 mA
Package Power Dissipation PDSee graph — W
Operating Ambient Temperature T ARange N –20 to 85 ºC
Range Q –40 to 105 ºC
Maximum Junction Temperature TJ(max) 150 ºC
Storage Temperature Tstg –55 to 150 ºC
Dual Full-Bridge Motor Driver
2916
3
Allegro MicroSystems, Inc.
115 Northeast Cutoff, Box 15036
Worcester, Massachusetts 01615-0036 (508) 853-
5000
www.allegromicro.com
V
BB
24
23
22
21
20
19
18
17
16
15
14
13
GROUND
GROUND
2B
OUT
SENSE
2
2
E
2A
OUT
1A
OUT
1
E
SENSE
1
1B
OUT
01
I
LOAD SUPPLY
Dwg. PP-047
1
2
3
4
5
6
7
8
9
12
11
10
9
GROUND
GROUND
02
I
12
I
PHASE
2
V
REF 2
2
RC
V
CC
1
RC
V
REF 1
PHASE
1
11
I
LOGIC SUPPLY
PWM 2
PWM 1
Q
1
Q
2
2
1
V
REF 2
GND
GND
GND
GND
6
5
4
3
2
1
44
43
42
41
40
28
27
26
25
24
23
22
21
20
19
18
Dwg. PP-006A
1
2
PWM 1
PWM 2
LOGIC SUPPLY
OUT
1A
E
1
SENSE
1
I
01
V
REF 1
PHASE
1
Q
1
RC
1
I
11
OUT
1B
LOAD SUPPLY
E
2
OUT
2A
I
02
SENSE
2
PHASE
2
2
Q
RC
2
I
12
OUT
2B
V
CC
V
BB
NO CONNECTION
NO CONNECTION
NC NC
7
8
9
10
11
12
13
14
15
16
17 29
30
39
38
37
36
35
34
33
32
31
50 75 100 125 150
5
1
0
ALLOWABLE PACKAGE POWER DISSIPATION IN WATTS
TEMPERATURE IN °C
4
3
2
25
Dwg. GP-035B
R = 6.0°C/W
SUFFIX 'B', R = 40°C/W
SUFFIX 'LB', R = 55°C/W*
SUFFIX 'EB', R = 30°C/W
θJT
θJA
θJA
θJA
*Measured on a single-layer board, with 1 sq. in. of 2 oz copper area.
For additional information, refer to the Allegro Web site.
EB Package (PLCC)
LB Package (SOIC)
1
2
3
4
5
6
7
8
9
24
23
22
21
20
19
18
17
16
15
14
13
12
11
10
9
θ
2
θ
1
V
CC
2
V
BB
1
GROUND
GROUND GROUND
GROUND
02
I
12
I
PHASE
2
V
REF 2
2
RC
1
RC
V
REF 1
PHASE
1
11
I
2B
OUT
SENSE
2
2
E
2A
OUT
1A
OUT
1
E
SENSE
1
1B
OUT
01
I
LOAD
SUPPLY
LOGIC
SUPPLY
Dwg. PP-005
PWM 1
PWM 2
Power Dissipation
B Package (DIP)
Dual Full-Bridge Motor Driver
2916
4
Allegro MicroSystems, Inc.
115 Northeast Cutoff, Box 15036
Worcester, Massachusetts 01615-0036 (508) 853-
5000
www.allegromicro.com
Limits
Characteristic Symbol Test Conditions Min. Typ. Max. Units
Output Drivers (OUTA or OUTB)
Motor Supply Range VBB 10 — 45 V
Output Leakage Current ICEX V
OUT = VBB — < 1.0 50 μA
V
OUT = 0 — <–1.0 –50 μA
Output Sustaining Voltage VCE(sus) I
OUT = ±750 mA, L = 3.0 mH 45 — — V
Output Saturation Voltage VCE(SAT) Sink Driver, IOUT = +500 mA — 0.4 0.6 V
Sink Driver, IOUT = +750 mA — 1.0 1.2 V
Source Driver, IOUT = –500 mA — 1.0 1.2 V
Source Driver, IOUT = –750 mA — 1.3 1.5 V
Clamp Diode Leakage Current IR V
R = 45 V — < 1.0 50 μA
Clamp Diode Forward Voltage VF I
F = 750 mA — 1.6 2.0 V
Driver Supply Current IBB(ON) Both Bridges ON, No Load — 20 25 mA
I
BB(OFF) Both Bridges OFF — 5.0 10 mA
Control Logic
Input Voltage VIN(1) All inputs 2.4 — — V
V
IN(0) All inputs — — 0.8 V
Input Current IIN(1) VIN = 2.4 V — <1.0 20 μA
VIN = 0.8 V — – 3.0 –200 μA
Reference Voltage Range VREF Operating 1.5 — 7.5 V
Current Limit Threshold VREF/V
SENSE I
0 = I1 = 0.8 V 9.5 10 10.5 —
I
0 = 2.4 V, I1 = 0.8 V 13.5 15 16.5 —
I
0 = 0.8 V, I1 = 2.4 V 25.5 30 34.5 —
Thermal Shutdown Temperature TJ — 170 — °C
Total Logic Supply Current ICC(ON) I0 = I1 = 0.8 V, No Load — 40 50 mA
I
CC(OFF) I
0 = I1 = 2.4 V, No Load — 10 12 mA
Fixed Off-Time toff R
T = 56 kΩ, CT = 820 pF — 46 — μs
ELECTRICAL CHARACTERISTICS at TA = +25°C, TJ ≤ 150°C, VBB = 45 V, VCC = 4.75 V to 5.25
V, VREF = 5.0 V (unless otherwise noted).
(at trip point)
Dual Full-Bridge Motor Driver
2916
5
Allegro MicroSystems, Inc.
115 Northeast Cutoff, Box 15036
Worcester, Massachusetts 01615-0036 (508) 853-
5000
www.allegromicro.com
APPLICATIONS INFORMATION
PWM CURRENT CONTROL
The UDx2916 dual bridges drive both windings of a bipolar
stepper motor. Output current is sensed and controlled
independently in each bridge by an external sense resistor, RS ,
internal comparator, and monostable multivibrator.
When the bridge is turned on, current increases in the motor
winding and it is sensed by the external sense resistor until the
sense voltage, VSENSE , reaches the level set at the comparator
input:
ITRIP = VREF/10 RS
The comparator then triggers the monostable, which turns off
the source driver of the bridge.
The actual load current peak will be slightly higher than the
trip point (especially for low-inductance loads) because of the
internal logic and switching delays. This delay, td , is typically
2 μs. After turn-off, the motor current decays, circulating
through the ground-clamp diode and sink transistor. The
source driver off-time (and therefore the magnitude of the
current decrease) is determined by the external RC timing
components of the monostable:
toff = RTCT
where:
RT = 20 to 100 kΩ, and
CT = 100 to 1000 pF.
The fi xed off-time should be short enough to keep the current
chopping above the audible range (< 46 μs) and long enough
to properly regulate the current. Because only slow-decay
current control is available, short off times (< 10 μs) require
additional efforts to ensure proper current regulation. Factors
that can negatively affect the ability to properly regulate the
current when using short off times include: higher motor-
supply voltage, light load, and longer than necessary blank
time.
When the source driver is re-enabled, the winding current (the
sense voltage) is again allowed to rise to the comparator’s
threshold. This cycle repeats itself, maintaining the average
motor winding current at the desired level.
Loads with high distributed capacitances may result in high
turn-on current peaks. This peak (appearing across RS) will
attempt to trip the comparator, resulting in erroneous current
control or high-frequency oscillations. An external RCCC
time delay should be used to further delay the action of the
comparator. Depending on load type, many applications will
not require these external components (SENSE connected to E).
PWM OUTPUT CURRENT WAVE FORM
LOAD CURRENT PATHS
+
–
0
Dwg. WM-003-1A
V
PHASE
I
OUT
t
d
t
off
I
TRIP
Dwg. E P-006-1
RS
BB
V
BRIDGE ON
SOURCE OFF
ALL OFF
Dual Full-Bridge Motor Driver
2916
6
Allegro MicroSystems, Inc.
115 Northeast Cutoff, Box 15036
Worcester, Massachusetts 01615-0036 (508) 853-
5000
www.allegromicro.com
LOGIC CONTROL OF OUTPUT CURRENT
Two logic level inputs (I0 and I1) allow digital selection of the motor
winding current at 100%, 67%, 33%, or 0% of the maximum level per the
table. The 0% output current condition turns off all drivers in the bridge and
can be used as an OUTPUT ENABLE function.
CURRENT-CONTROL TRUTH TABLE
l
0 I
1 Output Current
L L VREF/10 RS = ITRIP
H L VREF/15 RS = 2/3 ITRIP
L H VREF/30 RS = 1/3 ITRIP
H H 0
These logic level inputs greatly enhance the implementation of microprocessor
controlled drive formats.
During half-step operations, the I0 and I1 allow the microprocessor to
control the motor at a constant torque between all positions in an eight-step se-
TYPICAL APPLICATION
quence. This is accomplished by digitally selecting
100% drive current when only one phase is on and
67% drive current when two phases are on. Logic
highs on both I0 and I1 turn-off all drivers to allow
rapid current decay when switching phases. This
helps to ensure proper motor operation at high step
rates.
The logic control inputs can also be used to
select a reduced current level (and reduced power
dissipation) for "hold" conditions and/or increased
current (and available torque) for start-up condi-
tions.
GENERAL
The PHASE input to each bridge determines
the direction motor winding current fl ows. An in-
ternally generated dead time (approximately 2 μs)
prevents crossover currents that can occur when
switching the PHASE input.
All four drivers in the bridge output can be
turned-off between steps (I0 = I1 ≥ 2.4 V), result-
ing in a fast current decay through the internal
output clamp and fl yback diodes. The fast current
decay is desirable in half-step and high-speed ap-
plications. The PHASE, I0,and I1 inputs fl oat high.
Varying the reference voltage, VREF , pro-
vides continuous control of the peak load current
for micro-stepping applications.
Thermal protection circuitry turns-off all
drivers when the junction temperature reaches
+170°C. It is only intended to protect the device
from failures due to excessive junction tempera-
ture and should not imply that output short circuits
are permitted. The output drivers are re-enabled
when the junction temperature cools to +145°C.
The UDx2916 output drivers are optimized
for low output saturation voltages—less than 1.8 V
total (source plus sink) at 500 mA. Under normal
operating conditions, when combined with the ex-
cellent thermal properties of the package designs,
this allows continuous operation of both bridges
simultaneously at 500 mA.
FROM
μP
V
REF
Dwg. EP-008B1
V
BB
FROM
μP
1
2
3
4
5
6
7
8
9
24
23
22
21
20
19
18
17
16
15
14
1312
11
10
9
θ
2
V
CC
2
V
BB
1
V
REF
+5 V
STEPPER
MOTOR
R
S
R
S
R
C
R
C
R
T
C
T
C
C
C
C
+
PWM 1
PWM 2
θ
1
820 pF 56 kΩ
C
T
820 pF
56 kΩ
R
T
TRUTH TABLE
PHASE OUTA OUTB
H H L
L L H
Dual Full-Bridge Motor Driver
2916
7
Allegro MicroSystems, Inc.
115 Northeast Cutoff, Box 15036
Worcester, Massachusetts 01615-0036 (508) 853-
5000
www.allegromicro.com
Current Sensing
To minimize current sensing inaccuracies caused by ground trace
IR drops, each current-sensing resistor should have a separate
return to the ground terminal of the device. For low-value sense
resistors, the IR drops in the PCB can be signifi cant and should
be taken into account. The use of sockets should be avoided as
their contact resistance can cause variations in the effective value
of RS.
Generally, larger values of RS reduce the aforementioned effects
but can result in excessive heating and power loss in the sense
resistor. The selected value of RS should not cause the absolute
maximum voltage rating of 1.5 V, for the SENSE terminal, to be
exceeded. The recommended value of RS is in the range of:
RS = 0.75 / ITRIP(max) ± 50% .
If desired, the reference input voltage can be fi ltered by placing
a capacitor from REFIN to ground. The ground return for this
capacitor as well as the bottom of any resistor divider used
should be independent of the high-current power-ground trace to
avoid changes in REFIN due to IR drops.
Thermal Considerations
For reliable operation, it is recommended that the maximum
junction temperature be kept below 110°C to 125°C. The
junction temperature can be measured best by attaching a
thermocouple to the power tab or batwing of the device and
measuring the tab temperature, TTAB. The junction temperature
can then be approximated by using the formula:
TJ = TTAB + (2 × ILOAD × VF × RθJT) ,
where VF can be chosen from the electrical specifi cation table
for the given level of ILOAD. The value for RθJT is approximately
6°C/W for both package styles.
The power dissipation of the batwing packages can be improved
20% to 30% by adding a section of printed circuit board copper
(typically 6 to 18 square centimeters) connected to the batwing
terminals of the device.
The thermal performance in applications that run at high load
currents, high duty cycles, or both, can be improved by adding
external diodes from each output to ground in parallel with the
internal diodes. Fast-recovery (≤200 ns) diodes should be used to
minimize switching losses.
Load Supply Terminal
The load supply terminal, VBB, should be decoupled with an
electrolytic capacitor (≥47 μF is recommended), placed as close
to the device as is physically practical. To minimize the effect of
system ground IR drops on the logic and reference input signals,
the system ground should have a low-resistance return to the
load supply voltage.
Fixed Off-Time Selection
With increasing values of tOFF, switching losses decrease, low-
level load current regulation improves, EMI reduces, PWM
frequency decreases, and ripple current increases. The value of
tOFF can be chosen for optimization of these parameters. For
applications where audible noise is a concern, typical values of
tOFF should be chosen in the range of 15 to 35 μs.
APPLICATION NOTES
Dual Full-Bridge Motor Driver
2916
8
Allegro MicroSystems, Inc.
115 Northeast Cutoff, Box 15036
Worcester, Massachusetts 01615-0036 (508) 853-
5000
www.allegromicro.com
Package B, 24-pin DIP
External batwings, Pins 6, 7, 18, and 19 are fused internally
2
0.018
1
24
A
Dimensions exclusive of mold flash, gate burrs, and dambar protrusions
Exact case and lead configuration at supplier discretion within limits show
n
ATerminal #1 mark area
For Reference Only
(reference JEDEC MS-001 BE)
Dimensions in millimeters
5.33 MAX
0.46 ±0.12
1.27 MIN
6.35 +0.76
–0.25
3.30 +0.51
–0.38
10.92 +0.38
–0.25
30.10 +0.25
–0.64
1.52 +0.25
–0.38
0.38 +0.10
–0.05
7.62
2.54
Package LB, 24-pin SOICW
External batwings, Pins 6, 7, 18, and 19 are fused internally
1.27
BReference pad layout (reference IPC SOIC127P1030X265-24M)
All pads a minimum of 0.20 mm from all adjacent pads; adjust as necessary
to meet application process requirements and PCB layout tolerances
B
0.20 ±0.10
0.41 ±0.10
2.20
0.65
9.60
1.27
21
24
A
15.40±0.20
2.65 MAX
10.30±0.33
7.50±0.10
C
SEATING
PLANE
C0.10
24X
For Reference Only
External batwings, Pins 6, 7, 18, and 19 are fused internally
(Reference JEDEC MS-013 AD)
Dimensions exclusive of mold flash, gate burrs, and dambar protrusions
Exact case and lead configuration at supplier discretion within limits shown
ATerminal #1 mark area
0.25
GAUGE PLANE
SEATING PLANE PCB Layout Reference View
4° ±4
0.27 +0.07
–0.06
0.84 +0.44
–0.43
21
24
Dual Full-Bridge Motor Driver
2916
9
Allegro MicroSystems, Inc.
115 Northeast Cutoff, Box 15036
Worcester, Massachusetts 01615-0036 (508) 853-
5000
www.allegromicro.com
UDN2916EB
Package EB, 44-pin PLCC
External batwings, Pins 7 through 17 and 29 through 39 are fused internally
2144
A
Dimensions exclusive of mold flash, gate burrs, and dambar protrusions
Exact case and lead configuration at supplier discretion within limits shown
ATerminal #1 mark area
For Reference Only
(reference JEDEC MS-018 AC)
Dimensions in inches, metric dimensions (mm) in brackets, for reference only
C
SEATING
PLANE
0.51
4.57 MAX
16.59 ±0.08
16.59 ±0.08
7.75 ±0.36
7.75 ±0.36
7.75 ±0.367.75 ±0.36
C0.10
44X
0.74 ±0.08
17.53 ±0.13
17.53 ±0.13
1.27
0.43 ±0.10
Copyright ©1994-2009, Allegro MicroSystems, Inc.
Allegro MicroSystems, Inc. reserves the right to make, from time to time, such de par tures from the detail spec i fi ca tions as may be required to per-
mit improvements in the per for mance, reliability, or manufacturability of its products. Before placing an order, the user is cautioned to verify that the
information being relied upon is current.
Allegro’s products are not to be used in life support devices or systems, if a failure of an Allegro product can reasonably be expected to cause the
failure of that life support device or system, or to affect the safety or effectiveness of that device or system.
The in for ma tion in clud ed herein is believed to be ac cu rate and reliable. How ev er, Allegro MicroSystems, Inc. assumes no re spon si bil i ty for its use;
nor for any in fringe ment of patents or other rights of third parties which may result from its use.
For the latest version of this document, visit our website:
www.allegromicro.com
